- A given atom will Absorb and Emit the SAME frequencies of E-M radiation.
- So a gas of hydrogen will produce an absorption line spectrum if it is
between you (your spectrograph) and a continuum light source, and an
emission line spectrum if viewed from a different angle.
- The E-M radiation frequencies absorbed/emitted map out the
allowed energy levels in the atom.
- It turns out that the allowed energy levels in an atom depend mostly on the
electric field configuration. So, Hydrogen, with one proton in the nucleus has
a different field configuration than does Helium with two protons - this is why the two atoms have
a different energy levels and different characteristic absorption and emission lines.
Wed Jan 14 15:31:54 PST 1998